Parking trolley for light aircraft

ABSTRACT

A parking trolley for light aircraft (1) with a couple of landing wheels (3,3), and a nose or rear supporting wheel (3&#39;), comprising a mainly T-shaped frame (2) with adjustable supporting surfaces (4, 5,6) for the landing wheels (3,3) and the supporting wheel (3&#39;). The T-frame is supported by wheels (12,13,14) at the free ends of the frame, the wheels being adjustable and lockable in a position with the turning axes of the wheels in parallel for transport of the parking trolley and light aircraft on the trolley by the aid of a traction vehicle. Furthermore, wheels (12,13,14) are adjustable to positions with their turning axes directed as radii of a turning point (9), alternatively a turning point (10) at a distance from turning point (9), which is connected with an anchoring means (11) in the ground, via a turning bolt. Parking trolley (2) with an attached light aircraft may, consequently, turn about one of the turning points dependent on the effect of the wind on the light aircraft to turn the latter upwing like a wind vane.

The present invention relates to a parking trolley for light aircraft ofthe kind as stated in the preamble of the following independent claim 1.

Light aircraft are commonly anchored by guys when they are parked on theground to be secured in case of wind. The guys are, on one hand attachedto the aircraft and, on the other hand secured to anchoring members,e.g. concrete blocks, provided on the ground. Such a manner of parkingis time consuming and bulky, as well as requiring hard work.Additionally, the aircraft rudder must be secured when the aircraft isparked, because strong wind aft may damage the rudder.

In order to ensure safe parking, such a parked light aircraft shouldstand upwind. This means that the parked light aircraft should be turnedwhen the wind direction changes. Such constant supervising of lightaircraft implies considerable strain both to private aircraft owners andto aero clubs, as well as to the servicemen in control towers onserviced airfields who must warn in case of sudden changes of theweather or when the wind direction turns 180° in case of strong wind.

It is previously known to provide light aircraft on a parking trolley asmentioned above in order to avoid the above mentioned problems in caseof parked light aircraft when the wind is strong and variable, theaircraft being secured on the parking trolley which can turn freelyabout a turning point. The wind influencing the aircraft will, thus,turn the aircraft and, thus, the trolley upwind in the same manner as awind vane.

A parking trolley of this kind is known from U.S. Pat. No. 4,360,175,but has not obtained a footing in Norway.

Disadvantages of said known parking trolley are that it is permanentlyattached to be rotatable at a defined place on the ground, and that theframe or carrier arms supporting the parked light aircraft are, in turn,supported by small elongated steel rollers rolling on the ground, sothat the carrying arms extend at a low level to permit the aircraft tobe run onto, and off the trolley. Said steel rollers which have a smalldiameter and form the wheels of the trolley are highly demanding asregards a smooth basis to permit even support on the carrying arms ofthe parking trolley, and to achieve a minimum of rolling frictionpermitting the parked light aircraft with the trolley to turn with thewind.

It is an object of the present invention to provide a parking trolleyfor light aircraft which does not show the above mentioned drawbacks anddisadvantages, and which permits the parking trolley to be used as atransport trolley for light aircraft as well, at least over minordistances on the airfield.

According to the invention this is achieved by the characterizingfeatures appearing from the characterizing part of the followingindependent claim 1, as well as the following dependent claims.

Such a turnable parking trolley with a parked light aircraft, asmentioned above, works according to a "wind vane principle" since saidtrolley/aircraft will alwise turn when influenced by any wind strongerthan fresh breeze, so that the nose of the aircraft will always face thewind. The aircraft is, naturally, attached to the parking trolley in asuitable manner, and the parking trolley is safely secured to the groundwhile retaining its turnability. Consequently, all work in connectionwith previously used securing of the light aircraft by the aid of guys,as mentioned above, is avoided.

When the light aircraft is to be placed on the parking trolley it ispreferably pulled onto the parking trolley by the aid of a winch, whichis preferably mounted on the trolley.

To get down from the parking trolley the light aircraft may either taxiunder its own power or it may be pulled by the aid of the winch.

In the following the invention will be disclosed in more detail withreference to an embodiment diagrammatically shown in the drawing, inwhich

FIGS. 1 and 1a show a perspective view of a parking trolley carrying aparked light aircraft, and

FIGS. 2 and 2a show a plan view at a slightly larger scale of theparking trolley according to FIGS. 1 and 1a.

In the drawing FIG. 1 shows a light aircraft 1 parked on a parkingtrolley 2. The landing gear 3 of aircraft 1 is secured by straps or inanother known manner to trolley 2, and the same goes for the supportingwheel of the aircraft, nose landing gear 3' in FIG. 1.

Parking trolley 2 is roughly T-shaped and consists of a transversemember 7, and a main member 8, extending orthogonally to member 7 whichpreferably consist of a cross beam 7 and a main beam 8, which arereleasably connected in order to permit the parking trolley to be packedand conveyed in a dismantled state from producer to buyer, which meansreduced space for transport and transport costs.

On said beams 7 and 8 three supporting surfaces 4, 5, 6 for the wheels3, 3' are provided and preferably show a fluted or rough surface toprovide for high friction against the aircraft wheels to prevent thewheels from sliding on the supporting surface. Supporting surfaces 4, 5,6 are preferably designed as roll on/roll off plates with a slightlyV-shaped longitudinal section, and are pivoted at the apex of theirV-shape in the parking trolley. Consequently, roll on/roll off platescan be turned to the ground with one or the other end to allow aircraftwheels 3,3' to run from one or the other side of said roll on/roll offplates. Also, aircraft wheels 3, 3' will be supported against rollingoff forwards as well as backwards in a parked state when the aircraft isclamped to the parking trolley. Roll on/roll off plates 4, 5 may be slidforwards and backwards on cross beam 7 for adaption of their mutualdistance to the distance between landing wheels 3,3' of the kind ofaircraft in question. Main beam 8 which is connected with cross beam 7acts as a support for supporting wheel 3' which in FIG. 1 and FIG. 1a isa rear supporting wheel, and a supporting nose wheel 3', respectively.In the embodiment shown in FIG. 1, however, roll on/roll off plates 4, 5are mutually connected by the aid of telescopic braces extending incross beam 7, so that the mutual distance between said plates 4, 5 maybe varied as mentioned. Such telescopic adjustment may also beincorporated in main beam 8 for adjustment of roll on/roll off plate 6.

The parking trolley according to the shown embodiments has two possibleturning points 9 and 10, respectively. When the trolley is used only oneturning point 9 or 10 is used and is selected dependent on the positionof supporting wheel 3'--in front of or behind landing gear 3. In FIG. 1turning point 9 is used, which is connected with a foundation 11 in theground, via a vertical attaching bolt which is connected with turningpoint 9 in the trolley. This also goes for the alternative embodimentshown in FIG. 1a, where turning point 9 is, however, displaced laterallyto the center of main beam 8, which will be described later.

The ends of parking trolley 2, 3, i.e. the free ends of cross beam 7 andmain beam 8, are supported by a wheel 12, 13, 14, respectively, eachwhich are rotatable about vertical axes and may be adjusted to andfirmly held in at least two positions, preferably in three positions.

As shown in FIGS. 2, 2a, the swingable wheel 12, 13 are lockable in twomain positions. In one main position, as shown in a full line in FIGS. 2and 2a, and wheels 12, 13, 14 are positioned for rolling along acircular path with its center in turning point 10.

In the second main position wheels 12, 13 and, if desired, wheels 14,14' as well, are positioned in parallel, i.e. with parallel turningaxes, for transport of the parking trolley per se or with an attachedaircraft If wheels 14, 14' do not adjust in parallel with wheels 12 and13 during transport of the trolley, this end of trolley 2 must be liftedin connection with an attachment hook on a vehicle to lift wheels 14,14' from the ground.

The above mentioned positions are adjustable and lockable wheels 12, 13,and 14 can also be positioned in a further position with their turningaxes in the same direction as radii to the second turning point 9 of theparking trolley, so that the wheels may run in circular paths with thecenter in said turning point in the same manner as disclosed above inconnection with turning point 10. The choice between turning point 9 or10 will depend on the undercarriage of the light aircraft.

In FIGS. 1 and 2 only one swingable wheel 14 is shown at the free end ofmain beam 8. In the alternative embodiment of FIGS. 1a and 2a two wheels14, 14' are shown, which may be adjusted and locked to roll alongcircular paths with a turning point 9 or 10 in the same manner asdisclosed above.

Wheels 14, 14' are placed laterally of main beam 8, as clearly shown inFIG. 2a, so as not to interfere with roll on/roll off plate 6 and, thusthe supporting wheel 3' of the aircraft when the latter is rolled ontoand down from the parking trolley.

With the above mentioned positioning of turning points 9, 10 laterallyof main beam 8, i.e. outside the longitudinal centre line of the parkingtrolley, a turning moment is achieved when the wind starts blowing fromstraight behind the aircraft. Also, the choice of mounting system andits design is less limited, since it will not interfere with supportingwheel 3' when the aircraft is to roll onto or down from the trolley.

I claim:
 1. A parking trolley for light aircraft (1) with a couple oflanding wheels (3,3), and a nose or rear supporting wheel (3'),comprising a substantially T-shaped frame (2) with supporting surfaces4, 5 for the landing wheels (3,3), and a supporting surface (6) for thesupporting wheel (3'), said T-frame (2) being at one turning point (9)arranged to be freely turnable about a vertical turning axis (11') inrelation to a firm attachment (11) in the ground, to which the T-frameis turnably connected, and being supported by freely rotatablesupporting members (12, 13, 14) at the two end portions of the T-frame,said parking trolley with a firmly clamped light aircraft swingingupwind in case of a wind load on the rudder of the aircraft,characterized in that the rotatable supporting members (12, 13, 14)consist of supporting wheels (12, 13, 14) having their wheel axesoriented like radii of said turning point (9), and with at least two ofthem (12,13) on the cross member (7) of T-frame (2) being releasablyheld and are swingable and lockable in a position with the wheel axes inparallel, preferably orthogonally to the main beam (8) of the T-frame,for turning a parking trolley about the firm point (11), and transportof the trolley with or without an attached aircraft, respectively.
 2. Aparking trolley as defined in claim 1, characterized in that the crossmember (7) and the main member (8) of the T-frame (2) consist of beams(7,8) which support roll on/roll off plates (4,5,6) forming thesupporting surfaces (4,5,6).
 3. A parking trolley as defined in claim 2,characterized in that roll on/roll off plates (4,5) and cross beam (7)are mutually adjustable towards and away from each other for adaption tothe landing gear (3,3) of the aircraft, and that roll on/roll off plate(6) is adjustable forwards and backwards on main beam (8) for adjustmentto the supporting wheel (3') of the aircraft.
 4. A parking trolley asdefined in claim 2, characterized in that roll on/roll off plates(4,5,6) are V-shaped and swingably mounted at the apex of the V-shapefor swinging from contact with the ground, i.e. roll on position, up toan attachment position for the aircraft landing gear (3,3').
 5. Aparking trolley as defined in claim 1, characterized in that twoalternative turning points (9 and 10) are provided at a mutual distancealong the main member (8) of the T-frame for use in case of lightaircraft (1) with a rear supporting wheel (3'), or a supporting nosewheel (3'), respectively being parked.
 6. A parking trolley as definedin claims 1 and 5, characterized in that the turning point (9 orpossibly 10) is arranged laterally of the center line of main member(8).
 7. A parking trolley as defined in claims 2, 3, or 4, characterizedin that a roll on/roll off plate (6') is provided centrally on crossmember (7) of the T-frame flush with the main member (8) for rolling theaircraft (1) onto/off the parking trolley (2) in both directions.
 8. Aparking trolley for light aircraft (1) with a couple of landing wheels(3,3), and a nose or rear supporting wheel (3'), comprising asubstantially T-shaped frame (2) with supporting surfaces 4,5 for thelanding wheels (3,3), and a supporting surface (6) for the supportingwheel (3'), said T-frame (2) being at one turning point (9) arranged tobe freely turnable about a vertical turning axis (11') in relation to afirm attachment (11) in the ground, to which the T-frame is turnablyconnected, and being supported by freely rotatable supporting members(12, 13, 14) at the two end portions of the T-frame, said parkingtrolley with a firmly clamping light aircraft swinging upwind in case ofa wind load on the rudder of the aircraft, characterized in that therotatable supporting members (12, 13, 14) consist of supporting wheels(12, 13, 14) having their wheel axes oriented like radii of said turningpoint (9), and with at least two of them (12,13) on the cross member (7)of T-frame (2) being releasably held and are swingable and lockable in aposition with the wheel axes in parallel, preferably orthogonally to themain beam (8) of the T-frame, for turning a parking trolley about thefirm point (11), and transport of the trolley with or without anattached aircraft, the cross member (7) and the main member (8) of theT-frame (2) consisting of beams (7,8) which support roll on/roll offplates (4,5,6) forming supporting surfaces (4,5,6), wherein the rollon/roll off plates (4,5,6) are V-shaped and swingably mounted at theapex of the V-shape for swinging from contact with the ground, i.e. rollon position, up to an attachment position for the aircraft landing gear(3,3').